Mine-door.



PA TENTED SEPT. 4, 1906'.

C. R. ANDERSON.

MINE DOOR.

APPLICATION FILED JAN. 17, 1900.

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No830,281. PATENTED SEPT. 4, 1906. 0. R. ANDERSON.

MINE DOOR.

APPLICATION TILED JAN.17, 1906.

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CECIL R. ANDERSON, OF BEN AVON, PENNSYLVANIA.

MINE-DOOR.

Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed January 17, 1906. Serial No. 296,464.

To all whom, it may concern:

Be it known that I, CECIL R. ANDERSON, a citizen of the United States, residing at Ben Avon, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Mine-Doors, of which the following is a specification, refer ence being had therein to the accompanying drawings.

Mine-doors which open and close automatically require comparatively little power for the closing movement, the greatest power being required for starting them from the fullopen position. When the full power is exerted throughout the entire movement, the doors shut with a slam which is very damaging to them and to the actuating mechanism.

The primary object of this invention is to provide for exerting the full closing power only when starting the doors from open position, the arrangement being preferably such that the power is decreased gradually, whereby the doors are closed easily or quietly and without injury thereto or to the mechanism which actuates them.

Tith those automatically-operating doors wherein the closing mechanism is constantly active and unvarying the'entire resistance thereof is encountered and must be counteracted at the beginning of the opening movement, thereby subjecting the mechanism to sudden and severe strain.

A further object of the invention is to provide dooractuating mechanism the resistance of which increases gradually as the door opens, thereby relieving the mechanism of strain and danger of injury incident to suddenly encountering the maximum closing power.

As the invention may be adapted to doors and operating mechanisms of various types the principles underlying the same may be variously embodied, one adaptation thereof being shown in the accompanying drawings, wherein Figure 1 is a top plan View of a double weight-operated door with the invention applied thereto. Fig. 2 is a side elevation of the lower portion of the operating mechanism. Fig. 3 is a front view of the doors when closed, the view being taken at line 3 3 of Fig. 1. Fig. 4 is a view, enlarged, of a portion of the mechanism, taken at line 4 4 of Fig. 1; and Fig. 5 is a similar view showing the weighted arm raised.

Referring to the drawings, 2 designates the minetrack, and 3 and 3 the posts at opposite sides thereof, to which, respectively, doors 4 and 4 are hinged to swing in opposite directions. Paralleling track 2 is rock-shaft 5 having a series of inwardly-extending crankarms 6, to the inner ends of which is secured the elongated depressor-bar 7, which lies close to one of the track-rails and is normally raised, as in Figs. 1 to 4. 8 is a relatively short rock-shaft on the outer side of shaft 5 with its crank-arms 8 connected by links 9 to two of a series of crank-arms 10, projecting from shaft 5. Rising from shaft 8 is arm 11, connected by link 12 to door 4, which is thus opened and closed by the rocking of shaft 8.

For causing the doors to swing simultaneously in opposite directions brackets 13 pro jecting therefrom are connected by bar 14. WVith the outer ends of arms 10 weighted tread-bar 7 is held normally raised and the doors closed. When, however, bar 7 is depressed by the wheels of an approaching car, shaft 8 is so rocked as to open the doors, the latter being closed and the parts returned to normal position by weighted arms 10 as soon as the cars pass through and off of bar 7.

Hinged to arms 10 and adapted to swing upwardly thereon are the arm extensions 15, 16, 17, and 18, provided, respectively, with weights 15, 16, 17, and 18. A stop 19 on each of arms 10 is adapted to engage the under edge of the hinged arm extension and lift the same. For stopping the downward movement of the hinged arm extensions I provide uprights or rests 15, 16, 17, and 18, (here shown of gradually-incre.=1sing height,) so that as shaft 5 is oscillated bythe depression of bar 7 one after the other of arms 10 raises its weighted extension, thus gradually lifting the series until upon the complete depression of bar 7 and the full opening of the doors all of the weights are lifted and acting counter to the door-opening force. All of the weights are thus made available for starting the closing movement of the door without subjecting the mechanism to the shock or strain incident to an initial raising of them all. WVhile all the weights exert pressure for starting the door from open position as soon as the ,car has passed bar 7, the hinged and weighted arm extensions are rendered inactive one by one by resting on their respective supports of varying height. Thus the door is caused to close under a gradually-decreasing force which prevents slamming and the jarring or racking of the ports.

The two central crank-arms to which shaft 8 is connected are here shown each with a weight 10 mounted directly thereon, no pivoted weight-carrying-arm extension being used. Thus weights 10 constantly oppose the opening movement of the door and are quite sufficient to hold the same normally closed. It will be understood, however, that a greater or less number of constantly-acting weights may be provided.

As means for increasing and decreasing the power as the door opens and closes may be variously embodied it will be understood that the invention is not restricted to the by the devices are rendered active succes-' sively as the door opens and inactive successively as the door closes.

2.' The combination of a door, car-actuated mechanism adapted to open the door,

weights for resisting the movement of said mechanism, and means whereby the weights are lifted successively as the door opens and are rendered inactive successively as the door closes.

3. The combination of a door, car-actuated the door opens to first lift the weight from the lowermost support and the weights successively from the higher supports.

5. The combination of a door, a car-deflected bar connected to and adapted to open the door when deflected, a series of weights, and means whereby one after the other of the weights are lifted as the bar is depressed.

6. The combination of a door, a car-deflected bar connected to and adapted to open the door when deflected, a series of arms adapted to be raised by the bar when deflected, a jointed weighted extension for each arm, and supports for sustaining said weighted arm extensions in their lowered positions.

7. The combination of a door, -a car-de' flected bar connected to and adapted to open the door when deflected, a shaft connected to and adapted to be rocked by said bar, a series of weighted arms on the shaft, each having an upwardly-breaking joint, and supports of different heights for sustaining the weighted outer portions of said arms.

In testimony whereof I aflix my signature in presence of twowitnesses.

CECIL R. ANDERSON. Witnesses:

J. M. NESBIT, MARGARET HUGHES. 

